Been trying to figure out an economical way to run methanol on a street car while in boost only. (at 800-900whp levels)

What would the foreseeable problems be with running a carburetor and fuel injection simultaneously? Could a carb with no fuel supplied to it (once the float bowls were empty) act as a make shift throttle body?

I figure I could use a very cheap megasquirt setup to batch fire 8 injectors and cruise around town on 87 octane pump fuel.

Then I could have a separate fuel system for the carb. side of things with 100% methanol for boost.


Pro's
1.) No intercooler would be needed for huge boost levels.
2.) Running the car on standard fuel would help get the temps up and keep the crank from being saturated with methanol/corrosion.
3.) Monster fuel injectors and fuel pumps are not required to supply a methanol fueled carb.

Cons.

1.) This wouldn't work well "on the fly".
2.) Fuel injected cruising may be "finicky".


I believe the "Rons Flying Toilet" setups use something similar. They use a primer kit to start the engine and cruise around the pits at light throttle, then use straight methanol down the track.

Would look Similar to this...

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Could also run a carb spacer injector setup with 2 injectors for idle and cruise only to simplify the setup.

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Thoughts?

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wouldn't it be much easier to run a ms3 with dual fuel or fuel swithcing with 2 seperate fuel systems

 

From a cost perspective i dont think so. The injectors and pump alone required to make 800-900 hp on methanol are crazy expensive compared to a home modded blow thru carb. You also wouldnt have to worry about part throttle/cruise/power valve tuning with the carb. Just drop in huge jets and go.

 

Simple Gas system (carb) and NOS system (using Methanol) has been done a lot over the years. The Methanol system you mention is basically an on/off system.

Hard to get much easier than that. Oldsmobile in 1963 had a turbo system and used Water Methanol to add power and reduce knock at higher boost levels.
Deal is the water bottle being empty killed more than a few of those engines.

CONSTANTLY refilling the bottle (be it water/methanol or NOS) is a PIA too. Why people just went turbos in the first place.

Tom V.

 

Appreciate the input Tom! How is what you suggest different than the typical Aux. meth/water injection system?

Looking for the most economical way to run a 100% methanol fueled FI drag car. While retaining the ability to idle and cruise the streets on pump gas. After looking at the prices of injectors and fuel pumps able to support 900hp (on methanol)... I'd think a home built blow-thru carb. would be the cheapest way to fuel a methanol setup. I can't imagine there is an economical NOS plate system out there capable of supplying 900HP worth of fuel on methanol. A microsquirt controller would be able to handle the pump gas portion on a set of factory injectors. I would use two 10 gallon fuel cells.

 

"Economical" GOOD Dual fuel systems are never cheap.

Tom V.

 

I hear you... Doesn't have to be "Good" Just has to putt around town and to the track on pump gas.

 

If you had a Pontiac Tri-power GTO Engine you could putt around on a small 2-bbl on the street and then add the additional fuel/ Methanol on the end carbs to get the HP number with boost.

If the center carb went a bit lean you could "over compensate" with the Methanol (On-OFF) calibration at the track. But you don't have a TRI-POWER GTO, >(

Tom V.

 

Holley type carb with gas in the primary and methanol in the secondary.

 

I think you'd run into equal distrobution issues with the FWD and AFT cylinders, no?

 

Not if you have the capacity to be a little creative. You want to think outside the box, so think outside the box. For instance, a spread bore divides the air flow, therefore fuel flow, approximately 30% primary 70% secondary. Distribution fuel directing tricks like a booster spivy or two, butterfly angle, contour of the manifold entry, or a step or trip in a spacer between the carb and manifold can put fuel where you want it. A high velocity pullover circuit (as found in some Rochester 2 bbls. and QJets and other carbs) from the secondary into the primary can be rigged so at high flow some meth is discharged in the primary.

 

I like the idea of it, but I can't see it working without the ability to heavily modify and or make your own carb. I'd think you'd have a varying mix of two very different fuels in all the cylinders. Your tune would be limited by the percentage of "race gas" you could get into the forward cylinders. And I'd think this would throw the mixture/tune off in the aft cylinders. I could see something like pumpgas/race gas working better in that scenario.

 

Is there an issue just driving with the engine in vacuum on the carb. Then in boost hit it with meth and fuel? Not worring what the carb is doing fuel wise. I would think at some point it would go lean, but if the primary fuel is methanal at that point and you are tuning for it how cares? If the carb was repeteable in its action (leaned out at the same rpm every time) you would have a base to tune against?
Just brain storming. Maybe a nonboost referenced carb? What happens in a carb when boost gets higher than 14.7?
Be safe, schick

 

what about an air director type deal, bypass the carb when on fuel injection and when in boost have a selector door move to a blow thru mode. that way the bowls would always be filled. only thing id be concerned with is popping a motor when your going from cruise to boost, it takes time to fill the bowls with the setup your talking about.

 

Biggest issue is methanol is corrosive and unless you drain and flush meth set up every night you WILL eventually get corrosion.
Is E85 local too you? if so just built MS2E or MS3 and add in a GM flex fuel sensor, them and connectors are all over ebay. Sensor makes it worthwhile so you can fill up with 93 around town and if you have proper tune/map your much safer.
Wish I could show you what happend to my bosses 600cc mini sprint, he raced on Friday got sick and didnt get back to it till Monday, DANG but it was bitch to get them carbs cleaned out, he has since been running 93 and never had clogging issues.
http://www.turbomirage.com/water-alcohol-injection-parts-list.html Here is better idea, You can also BUY specific mix product called BoostJuice from Snow Performance, BUT a couple gallon of washer fluid is so much easier to deal with, or dump in denatured alcohol and water.
You can eve use straight ethanol and its as cheap/cheaper and much less destructive. With washer fluid you can also pull for wipers as needed or make a bypass filler from water injection.
Dual fuel with methanol is lot of hassle unless you plan accordingly, stainless tank, lines, parts. Lots of prep and flushing.
In my opinion I HATE methanol, and cops smell it they can give you hassle.

 

I run e85 with meth injection...and an intercooler now. It performs nothing like straight methanol. The locals that use methanol don't do anything fancy to their tanks/lines/system and run it all year. Most are using it with fuel injection though. I've heard the horror stories about methanol, but never seen them. I know a couple friends using it on their blown dragsters and also have zero problems. Alot has to do with the location/moisture content in the air, and the type of methanol used. I hear oxygenated is the worst maintenance wise. the new TFE rubber brained lines can be used with methanol as well. Though the majority of my lines are SS now. I have a poly tank with no foam.

 

Nothing wrong with TUNER's idea using the Spread Bore Holley Carb.

Tri-Power carbs from a Pontiac, 66 Olds 442, or 427 Corvette were basically the same concept. Cruise around on the center carb and them 'Let Her Buck" with the end carbs.

Basically a on off switch similar to a NOS switch.

So the E-85 fuel would work ok with the newer type carbs and gaskets but you still need some carb background to make it work. Most are "Button Boys" these days vs "Carb Guys".
And a couple of UEGO sensors would make life a lot easier.

Just saying. A good idea using old school parts.

Tom V.

 

How would it work with pump gas and methanol and a 30/70 split? No matter what you did the forward cylinders would have a much smaller percentage of methanol would they not? If you were to try and compensate by increasing the aft jet size it would flood the rear cylinders. I'm all for the idea of it, but with out centrally located boosters, how could it work?

 

would some sort of mechanical port injection work? fogger nozzles in each running, triggered by boost or rpm switch, fuel ramped by boost and load?

 

Mechanical inj. would work great as it has for years now. But it's not an economical solution IMO. Might as well spend the 5k on methanol capable injectors/ECU/Pump if you were to go that route.